Provided is a nautical sector, in particular a catamaran boat including a first catamaran craft functioning independently, having a prevailing direction of longitudinal development along the median axis (x) and including a bow, a stern, motor means and directional means; a second catamaran craft functioning independently, having a prevailing direction of longitudinal development along the median axis (x) and including a bow, a stern, motor means and directional means, where said first catamaran craft and said second catamaran craft each include joining means for their mutual stable coupling, obtained matching the relative sterns, on a transverse junction plane (Π), to carry out said catamaran boat able to function as a single unit.